linux-kernel - [PATCH v4 29/31] fs/resctrl: Add interface for per-resource debug info files

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250429003359.375508-30-tony.luck@intel.com>
Date: Mon, 28 Apr 2025 17:33:55 -0700
From: Tony Luck <tony.luck@...el.com>
To: Fenghua Yu <fenghuay@...dia.com>,
	Reinette Chatre <reinette.chatre@...el.com>,
	Maciej Wieczor-Retman <maciej.wieczor-retman@...el.com>,
	Peter Newman <peternewman@...gle.com>,
	James Morse <james.morse@....com>,
	Babu Moger <babu.moger@....com>,
	Drew Fustini <dfustini@...libre.com>,
	Dave Martin <Dave.Martin@....com>,
	Anil Keshavamurthy <anil.s.keshavamurthy@...el.com>,
	Chen Yu <yu.c.chen@...el.com>
Cc: x86@...nel.org,
	linux-kernel@...r.kernel.org,
	patches@...ts.linux.dev,
	Tony Luck <tony.luck@...el.com>
Subject: [PATCH v4 29/31] fs/resctrl: Add interface for per-resource debug info files

There are some status registers on each of the telemetry aggregators.
Users may need to view these to understand unexpected event counter
values.

Add the file system support for a "status" file in each mon_capable
resource directory in the "info" directory. This will only be present if
the file system is mounted with the "-o debug" option. It will only have
content for resources that provide a rdt_resource::info_debug() routine.

Signed-off-by: Tony Luck <tony.luck@...el.com>
---
 include/linux/resctrl.h |  1 +
 fs/resctrl/rdtgroup.c   | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index 3ae50b947a99..675cfbe3e6c6 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -299,6 +299,7 @@ struct rdt_resource {
 	struct list_head	evt_list;
 	unsigned int		mbm_cfg_mask;
 	bool			cdp_capable;
+	void			(*info_debug)(struct seq_file *s);
 };
 
 /*
diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c
index 195e41eb73fb..5948e279b44c 100644
--- a/fs/resctrl/rdtgroup.c
+++ b/fs/resctrl/rdtgroup.c
@@ -1022,6 +1022,17 @@ static int rdt_shareable_bits_show(struct kernfs_open_file *of,
 	return 0;
 }
 
+static int rdtgroup_info_debug_show(struct kernfs_open_file *of,
+				struct seq_file *s, void *v)
+{
+	struct rdt_resource *r = rdt_kn_parent_priv(of->kn);
+
+	if (r->info_debug)
+		r->info_debug(s);
+
+	return 0;
+}
+
 /*
  * rdt_bit_usage_show - Display current usage of resources
  *
@@ -1983,6 +1994,13 @@ static struct rftype res_common_files[] = {
 		.seq_show	= rdtgroup_closid_show,
 		.fflags		= RFTYPE_CTRL_BASE | RFTYPE_DEBUG,
 	},
+	{
+		.name		= "status",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdtgroup_info_debug_show,
+		.fflags		= RFTYPE_MON_INFO | RFTYPE_DEBUG,
+	},
 };
 
 static int rdtgroup_add_files(struct kernfs_node *kn, unsigned long fflags)
-- 
2.48.1